Abstract:

Through the study on the acoustic velocity of seawater with gas bubbles, the conclusion was obtained as follows. (1) The relationship between the bubble radius and the seawater depth was that the bubble radius was bigger as the seawater was shallower. (2) The relationship between the acoustic velocity and the bubble radius was that when the bubble content was very little, with the bubble radius becoming larger, the acoustic velocity increased gradually at first and then keep unchanged and finally decreased slowly, and the extent of the acoustic velocity variation was not large; when the bubble content increased gradually, with the bubble radius becoming larger, the acoustic velocity increased gradually, and the varying range of the acoustic velocity was different if the bubble content was varied. (3) The relationship between the acoustic velocity and the bubble content was that when the bubble content was small, with the bubble content increasing, the acoustic velocity decreased gradually; when the bubble content was larger and the bubble radius was smaller than the critical radius,  with the bubble content increasing, the acoustic velocity decreased gradually; when bubble radius was bigger than the critical radius, with the bubble content increasing, the acoustic velocity decreased at first and then increased gradually. Furthermore, in every state of the bubble content increasing the varying range of the acoustic velocity was different.

Key words: bubble radius, bubble content, gas hydrate, seawater, acoustic velocity